1. Field of the Invention
This invention relates to an exercise machine, more particularly to an elliptical exercise machine with partially overhanging foot members which permits a user's feet to be placed in a more natural position.
2. Description of the Related Art
The benefits of regular exercise to improve overall health, appearance and longevity are well documented in the literature. Elliptical cross trainers have become one of the most popular exercise machines on the market because of their proven ability to simultaneously exercise both the upper and lower body at the same time, thereby increasing the efficiency of the exercise. Because elliptical cross trainer machines guide the motion of the feet through a smooth, predominantly elliptical-shaped closed-loop path, elliptical cross trainers also offer a smooth, low-impact exercise, minimizing the risk of injury to the back, knees, hips, and ankles.
However, because elliptical cross trainers define the travel path of the user's feet rather than the exerciser defining their own foot motion, there can be discrepancies between the natural motion of the human body and the motion imposed on the exerciser by the elliptical cross-trainer machine.
As one example, stride length is one variable that is defined by elliptical cross trainers. Some people, based on their height or preferences, may want an exercise machine that provides a short stride length, while others may want a longer stride length. Many elliptical cross trainers have been optimized to target a stride length that appeals to a majority of users. Other elliptical cross trainers have adjustable stride length so that a user may increase or decrease the stride length to their individual preferences.
Another variable is stride width, or the spacing between the insoles of the feet. When a person is standing, a comfortable stance is to place the feet approximately shoulder width apart. However, while walking or running, a person tends to decrease their stride width so that they place their feet closer to the centerline of the body. In other words, during walking or running, the stride width narrows, converging toward one foot being placed in-line with the other. This is more akin to walking a tightrope. However, traditional elliptical cross-trainers have, to date, always maintained a relatively large stride width. Unlike a treadmill, where a user can define their own foot motion, and therefore can walk with a natural stride width, an elliptical trainer defines the foot motion for the user, forcing the user to maintain the stride width of the machine.
For exercise equipment, a measurement of this machine-defined stride width is known as Q-Factor. For example, a Q-Factor measurement for a bicycle would traditionally be defined as the distance between the vertical plane defined by the inside edge of the left pedal and the vertical plane defined by the inside edge of the right pedal. Similarly, in the case of an elliptical cross trainer, Q-Factor has traditionally been defined as the distance between the vertical plane defined by the inside edge of the left foot support platform and the vertical plane defined by the inside edge of the right foot support platform.
Because an elliptical cross trainer moves each foot support platform through a substantially elliptical closed loop path, and because the foot platforms must not interfere with each other or with any other component of the elliptical trainer during this travel, the Q-Factors for traditional elliptical trainers have always been positive numbers to prevent interferences. However, this forces a wide stance upon the exerciser, forcing a user to move their feet within two widely-spaced parallel planes. This wide stride width is unnatural.
An object of the present invention is to provide an exercise machine with all of the benefits of a traditional elliptical cross trainer, while allowing the user to chose a very narrow stride width.
Another object of the present invention is to provide an elliptical cross trainer with foot support platforms that move through a closed-loop path without interfering with one another, while having foot support platforms spaced so close to one another that a portion of each foot support platform crosses the centerline of the machine.